The instant invention relates to stamping presses and the like, and more particularly, to a novel measuring device for facilitating the adjustments of the shut heights of stamping presses.
Presses are widely used in the manufacturing industry to form elements or components for a wide variety of applications. Conventional presses generally include first and second press members, the first of which comprises a stationary member generally referred to as a bolster plate, and the second of which is movable toward and away from the first and is generally referred to as a ram. The bolster plate and the ram are adapted to carry material engaging elements called a die set whereby material engaged by the elements is formed as desired in the press. In this regard, the upper and lower die set elements, referred to as the punch and the die, respectively, are formed in generally complimentary interfitting configurations whereby they cooperate to form material interposed therebetween as the ram is moved into proximity with the bolster plate.
It is obvious that due to the wide variety of applications for presses of the above described type, each press must be adaptable for use with a variety of different die sets. Further, it is obvious that each die set must be specifically designed for each particular application, and that therefore the configurations and dimensions of different die sets can vary substantially. The thicknesses of work piece materials engaged by die sets can also vary substantially depending on the particular applications.
Accordingly, it is necessary to adjust the shut height of a press (the distance between the ram and the bolster plate when the ram is in its lowermost position) each time a new die set is used. Adjustments of this type are effected by adjusting the ram or the bolster plate of a press, or both, depending on the particular press, to achieve the desired postions of maximum relative proximity. Heretofore adjustments of this nature have been effected by time consuming trial and error methods which have required operators to make visual estimates of desired shut height settings and thereafter conduct test pressings to obtain the desired settings.
The instant invention provides a novel shut height measuring device which substantially simplifies press shut height adjustment procedures. More specifically, the instant invention provides a device for accurately measuring the distance between the ram and the bolster plate of a press when the ram is in the lowermost position of its cycle. Accordingly, when the device of the instant invention is utilized in combination with previously tabulated shut height data pertaining to a particular press-die set combination, adjustments of the press to obtain the desired shut height for the particular die set may be quickly and accurately effected without the costly and time consuming heretofore known methods. In this connection, it is obvious that the first time a die set is used in a particular press, the conventional trial and error steps must be used to obtain the desired shut height setting. However, by recording the desired shut height data for a particular die set-press combination as measured using the device of the instant invention, subsequent installations of the same die set in the press can quickly and easily be effected without trial and error steps.
The device of the instant invention generally comprises a substantially flat base member, a post which extends substantially perpendicularly upwardly from the base member, a slide block which is slidably mounted on the post, a slide rod which is mounted on the slide block and extends a predetermined distance upwardly therefrom in substantially parallel relation to the post, and a measuring element which is mounted on the slide block and which is operable to determine the position of the slide block relative to the base. In the preferred embodiment, the device also includes upper stop means which defines the uppermost position of the block on the post and clutch means which frictionally engages the post to adjustably retain the slide block at various relative positions thereon.
In use, the base is positioned on the bolster plate of a press and the press is then operated to cycle the ram through its position of maximum proximity with the bolster plate. As the ram moves downwardly in its cycle, it engages the upper end of the slide rod and moves it downwardly until the ram reaches its shut height position. The clutch means in the device holds the slide block on the post at the shut height position despite upward movement of the ram as it passes through its cycle. Accordingly, the reading on the measuring element can thereafter be used to determine the shut height of the press. In the preferred embodiment, the measuring element actually functions to indicate a relative value representing the distance of downward travel of the block from its uppermost position. If desired, the absolute shut height can be calculated by subtracting this relative value from the distance between the uppermost and lowermost points of the device when the block is in its uppermost position.
Devices representing the closest prior art to the instant invention of which the applicant is aware are disclosed in the U.S. Pat. No. 2,818,798 to Deykin; Webster, U.S. Pat. No. 3,051,078; Munschauer, Jr. et al, U.S. Pat. No. 3,162,232; Baker, U.S. Pat. No. 3,192,751; Holben, U.S. Pat. No. 3,246,496; Bergman, U.S. Pat. No. 3,334,581; Helrigel et al, U.S. Pat. No. 3,687,069; Baker, U.S. Pat. No. 4,033,252; Gundal, U.S. Pat. No. 4,133,260; Spanke et al, U.S. Pat. No. 4,166,415 and Hemmelgarn, U.S. Pat. No. 4,206,701. Of these patents, the U.S. Pat. No. 4,033,252 to Baker, and Helrigel et al, U.S. Pat. No. 3,687,069 relate to presses which include shut height indicating means while the other patents relate more generally to presses per se. None of the above patents, however, disclose or teach a measuring device which functions in the novel and simple way of the device of the instant invention and which is not an integral part of a press so that it can be used with a plurality of different presses. Further, the indicating devices disclosed in the above patents have substantial structural differences from the device of the instant invention and do not include clutch means for holding a shut height reading on the device as a press follows through in its cycle.
Accordingly, it is a primary object of the instant invention to provide a device for accurately measuring the shut heights of presses.
Another object of the instant invention is to provide an indicating device for simplifying press shut height adjustments.
Another object of the instant invention is to provide a device for measuring the shut height of a press wherein an indicator dial of the device is maintained at a shut height reading after the press has passed the shut height position of its cycle.
A still further object of the instant invention is to provide a shut height indicating device having a frictional clutch element which adjustably maintains a shut height measurement on the device.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.